ultra-sensitive charge spectroscopy from electrostatic force measurements
DESCRIPTION
A possible new method for Neutrino mass measurement. . Ultra-sensitive Charge Spectroscopy from Electrostatic Force Measurements. Introduction. We have already built a working, in air, prototype. Capable of very accurate voltage, charge and force measurement. - PowerPoint PPT PresentationTRANSCRIPT
ULTRA-SENSITIVE CHARGE SPECTROSCOPY FROM ELECTROSTATIC FORCE
MEASUREMENTS.A possible new method for Neutrino mass measurement.
Luke Selzer - Ultra-Sensitive Charge Spectroscopy
Luke Selzer - Ultra-Sensitive Charge Spectroscopy
Introduction We have already built a working, in air,
prototype. Capable of very accurate voltage, charge and
force measurement. Our aim was to complete construction on a
vacuumed version. Test Vacuum stability. Use new setup to study β- Decay in the 63Ni
sample.
Luke Selzer - Ultra-Sensitive Charge Spectroscopy
β- Decay Theory
no p e e
Fig 1. Quark level Feynman diagram of a β – decay.
2963Ni 30
63Cu e e
The chosen β- Decay candidate was 63Ni:
Main feature of β- Decay is the electron and electron anti-neutrino production:
Luke Selzer - Ultra-Sensitive Charge Spectroscopy
β- Decay Energy Spectrum Energy distribution for
the electron emissions.
Described by the “Fermi Function”.
Important to notice there is a cut off energy.
Fig 2. Example of a β- Decay electron energy spectrum
Luke Selzer - Ultra-Sensitive Charge Spectroscopy
The Kurie Plot Plot of linearized
version of β- Decay energy spectrum.
With non-zero neutrino mass the plot becomes non-linear.
Occurs at high electron energy values.
Fig 3. Kurie plot demonstrating effect of non-zero neutrino mass.
Luke Selzer - Ultra-Sensitive Charge Spectroscopy
Basic Principle Vane setup in Vacuum. Vane undergoes β- Decay. Electrons are emitted. Vane becomes positively
charged. Reaches an equilibrium
comparable to the upper electron energy bound.
Fig 4. Photograph of floating dummy Nickel sample in the current experiment.
Luke Selzer - Ultra-Sensitive Charge Spectroscopy
Measuring the Vane Voltage Vane is kept in place by a
red laser and the diode array.
Electrostatic correction force is controlled by the diodes
Vane held stationary by steadily increasing supply voltage.
Fig 5. Schematic diagram of the rotation control system.
Luke Selzer - Ultra-Sensitive Charge Spectroscopy
Vane Voltage Ramp Electrons emitted
ramp charge on vane. Vane becomes highly
charged and fewer electrons are emitted
Eventually only high energy electrons are able to escape.Fig 6. Graph modelling the proposed negated voltage
ramp on the vane due to electron emission.
Luke Selzer - Ultra-Sensitive Charge Spectroscopy
Output data from the experiment
β- Decay spectrum
Kurie PlotDifferential of the output data produces the energy spectrum
Linearized version of the energy spectrum should produce a kurie plot
Data Analysis
Luke Selzer - Ultra-Sensitive Charge Spectroscopy
The Current Experimental Set Up Neodymium magnetic suspension system . Infrared Laser control system.
Height and Rotation.
Levitation Control System
Levitation Zone
Rotation ControlDiodes and Laser
Rotation control electrode
Fig 7. Photographs taken of the current set up.
Luke Selzer - Ultra-Sensitive Charge Spectroscopy
Levitation System Infrared laser strikes top
edge of the plate. A feedback system is set up
with the control coil. Magnetic field strength is
continuously adjusted. Vane levitated due to
ferromagnetic properties. Vane is balanced in an
unstable fixed point.Fig 8. Simulation of magnetic field lines supporting the ferromagnetic Vane.
Luke Selzer - Ultra-Sensitive Charge Spectroscopy
Current Rotation Control Electrostatic rotation
control. HT D.C. voltage applied
to electrode.
Fig 8. Front view of the electrostatic field.
Fig 9. Top view of the electrostatic field .
The Nickel vane aligns with electrode.
Nickel is still levitated by magnetic field only.
Luke Selzer - Ultra-Sensitive Charge Spectroscopy
Calibration
External Laser applied to vane using a square wave form.
A voltage change is displayed, the amplitude linearly corresponds to the Laser’s photon force.
Order of magnitude of 5 x 10 -12 N. Pico Newton force measurement.
Fig 10. output data from a laser calibration run.
Luke Selzer - Ultra-Sensitive Charge Spectroscopy
The New Set Up Two height control
lasers Allows free rotation
through 360 degrees Allows us to see
preferred positions Vacuum system.
Fig 11. Photograph of new height control system to be placed into the vacuum system.
Luke Selzer - Ultra-Sensitive Charge Spectroscopy
New Rotation Control Sensitivity
Fig 13. Sensitivity plotted against angle of vane at varying electrode distances.
Fig 12. Simulation cross section of new rotation control setup with contours depicting the electric field values.
Luke Selzer - Ultra-Sensitive Charge Spectroscopy
…Finally. Current progress:
Prototype built and tested.Calibrated.Vacuum system is built undergoing vacuum
testing. Future applications:
Detailed conduction studies of various gases.Precise capacitance measurement.Large range of experiments requiring sensitive
force measurement.
Luke Selzer - Ultra-Sensitive Charge Spectroscopy
Thanks to Yorck and the Electronics Workshop.
Any further questions?